Method of mounting well equipment



April 1969 J. c. TRIPPLEHORN 3,438,404

METHOD OF MOUNTING WELL EQUIPMENT Filed July 11, 1966' 7 INVENTOR JAMESc. TRIPPLEHORN Wand ATro Nm United States Patent U.S. Cl. 140-93 2Claims ABSTRACT OF THE DISCLOSURE The method of attaching a resilientrod guide body to a rod to which the body can be applied by flexing, forinstance spreading the guide and sliding it over the end of the rod, orparting it at a longitudinal slot, the method including Winding of awire-like material onto the annular body to compress it tightly againstthe rod, the opposite ends of the wire terminating near the ends of thebody and the central portion of the wire going either over or under thebody so that a single length of wire can be used. The opposed ends ofthe wire are then prevented from unwinding by one of several differentmethods, including a longitudinal locking member passed under the bodyand extending to its ends to receive the ends of the wire.

This invention relates to improvements in well equipment such ascentralizers, stabilizers, and parafiin scrapers, and more particularlyrelates to the combination of improved body structures cooperating withimproved means for operatively attaching the structures to rods ortubing. The invention also teaches an improved method of applying suchbodies to well rod or tubing.

It is a principal object of the invention to provide improved resilientbody structures which are especially designed to cooperate with windingmeans to provide a very tight grip of the body on the rod or tubing, andat the same time provide large-area engagement therebetween so that thebody is in substantially full contact with the rod, as distinguishedfrom contact at a few points, such as is experienced where theengagement is metal-to-metal.

It is another important object of the present invention to provideimproved windings and improved techniques for locking the windings onthe body. In one preferred embodiment the locking means is located atonly the upper end of the body in view of the fact that most of thewear, impact, and damage tends to occur at the lower end of the body.

Still another object of the invention is to provide improved bodystructures made of resilient plastic material such as nylon or rubberand being shaped in an optimum manner to cooperate with the windingmeans which hold the body on the rod or tubing.

The present invention is described with reference to severalillustrative embodiments which generally comprise a resilient bodysurrounding a length of rod or tubing, hereinafter referred to as therod, by windings located at both ends of the body. In the event the bodyis a scraper or centralizer, the central portion of the body can includeraised ribs or scraper members. The illustrative embodiments showround-wire windings, although it is to be understood that the windingsneed not be circular-cross-section wire but may comprise other strip ortape-like materials. All such winding materials will be included in theterm wire as used hereinafter. There are a number of different Ways inwhich the windings can be wound on to the bodies and locked thereon, butsome winding procedures have advantages over others. For instance, itcan be desirable to apply the windings starting near the center of thebody and then winding outwardly toward the ends, especially in the caseof a rubber body in view of the fact that the rubber will be caused toflow away from the central portion toward the ends as the windings areapplied, thereby forming ridges of rubber at the extreme outer ends ofthe body and beyond the winding areas to that the windings do not tendto slip off of the ends of the body. Winding slippage in the axialdirection can be prevented on nylon bodies by molding the end portionswith helical thread-like grooves for receiving and locating the wires.It may also be desirable to split the body longitudinally to facilitateapplication thereof to rods having enlarged ends, for instance atupsets. In the case of rubber bodies it may also be desirable to addreinforcement fabrics to control the amount of rubber flow.

The winding of attaching means onto a body is especially advantageoussince it provides a better grip than a bolted or riveted collar ofreasonable size. For example, using wire of approximately one-eighthinch diameter it was found that when a winding was applied around arubber body with only pounds of tension on the Wire as it was applied, a2,500 pound end load applied to the assembly formed in this fashionfailed to cause axial slippage thereof, or dislodgement of the wire fromthe body.

As previously mentioned, it is desirable to have the wire ends locked inthe vicinity of the upper end of the body, or at least away from thelower end thereof when applied to a sucker rod. Several differentWinding procedures have been found useful for this purpose. For example,the wire can be placed beneath the body and then wound in bothdirections toward the center of the body and locked by twisting the endsof the Wire to gether in the central body zone. Another satisfactoryprocedure is to place a metal strip beneath the body and then wind thewire on the body departing in both directions from the center thereof,the metal strip having lugs at both ends to receive and lock the outerends of the windings, for instance by hammering the lugs down on thewire. Still another way of accomplishing this purpose is to provide ahollow tube which extends longitudinally through the body. Wire can thenbe wound onto the body starting at one end, passing over the centralzone of the body, and then completing the winding at the other end ofthe body, the latter end of the wire then being passed through the tubeand locked to the first end of the Winding by twisting the endstogether. In the case of a nylon body the tube can be eliminated and thebody can be provided with a longitudinal groove or bore running adjacentto the central bore through which the sucker rod passes. There are anumber of other winding procedures which can be used to accomplish asimilar purpose, these various procedures sharing a common advantage:namely, the wire windings tend to be self-equalizing so that a uniformgrip is provided all along the body. Tight squeezing of the body againstthe sucker rod prevents the entry of oil or other liquids into the areawhere the body engages and grips the rod, thereby preventing anylubrication of this area which might assist slippage under extremeaxial-loading conditions.

It is another important object of the present invention to provide animproved method for applying a resilient body to a rodlike member bywinding wire thereon, and more particularly, by winding the wire ontothe body following a certain procedure in order to obtain maximum grip.

Other objects and advantages of the present invention will becomeapparent during the following discussion of the drawings, wherein:

FIG. 1 is an elevation view of a resilient centralize! 3 or scraper bodysecured on a sucker rod by windings on its ends;

FIG. 2 is a sectional view taken along line 22 of FIG. 1;

FIG. 3 is a diagrammatic view showing the outline of the body and suckerrod in dashed lines and showing the placement of windings upon thisstructure such that their ends are locked together in the central zoneof the body;

FIG. 4 is a diagrammatic view similar to FIG. 3 but showing a metalstrip located beneath the body and serving to lock both ends of thewindings just beyond the outer ends of the body;

FIG. 5 is a view similar to FIG. 3 but showing the winding ends lockedat only one end of the body, preferably the upper end;

FIG. 6 is an elevation view of a plastic body made according to thepresent invention and having an external shape similar to the body shownin FIGS. 1 and 2; and

FIG. 7 is a partial view of a nylon body similar to FIG. 6 but whereinthe end portions of the body are provided with helical grooves topositively prevent slippage of the windings longitudinally of the body.

Referring now to the drawings, the tubing or rod-like member R to whichthe present structure is to be attached will ordinarily have acylindrical periphery, and since it v is extremely important inconnection with oil well rods that the surface not be nicked in any wayor welded to, the present structure must grip the rod securely withoutdamaging its surface or requiring heating of its metal duringinstallation. The present invention illustrates in FIGS. 1 and 2 asuitable rubber body 1%, and in FIGS. 6 and 7 suitable plastic bodies,preferably made of a material which can be conveniently molded, such asnylon which also exhibits a considerable degree of resilience. In FIGS.3, 4 and 5, the body portion is generally referred to by the referencenumeral it), although it is to be understood that this reference is notintended to exclude the plastic body 36. The body has an enlargedcentral portion 11 which in the present embodiment includes scraper orcentralizer blade portions 12 separated by grooves 13 through whichfluids can bypass the body structure as it is reciprocated up and downon the sucker rod. The outer ends of the body are substantially conicalas at 14 to reduce tendency to snag, although these outer ends could bemodified in shape, for example made cylindrical if desired for analternative embodiment. The plastic bodies shown in FIGS. 6 and 7 havesimilar shapes which include blade portions 32 separated by grooves 33in the central portion 31 of the body. These bodies are also shown ashaving conical end portions 34. In FIG. 7 the end portions includehelical thread-like grooves 35 which are molded to receive theparticular crosssectional shape and diameter of the winding stripmaterial to be applied, and which serve the purpose of preventingslipping of the winding in the axial direction represented by the arrowA.

The plastic body 36 should be longitudinally divided as for instancealong the lines D since in all probability the body cannot be slippedover the end of a sucker rod or length of tubing because of the tooljoints at the ends thereof. The rubber body shown in FIGS. 1 and 2 maybe likewise divided in two as shown at D in FIGS. 6 and 7, or the bodymay be slit along one side only so that it can be flexed open to receivethe rod R. In any event the body is provided with a central bore 16, or36, to receive the rod R and its bore should be sized to be a snug fiton the rod prior to the application of the windings.

In the case of a rubber body as shown in FIGS. 1 and 2 the resilience ofthe body would probably be suflcient to permit the passage of the wireor locking strap through the bore 16 by merely displacing some of therubber adjacent the rod R, although a longitudinal groove mayadvantageously be provided for this purpose, the groove opening into thebore 16. On the other hand, in connection with a harder plastic body 36a groove such as the groove 37 has to be molded into the body so that itcommunicates with the bore 36. Alternatively, the groove 3-7 maycomprise a completely separate bore passing through the body and offsetsomewhat from the main rod receiving bore 36.

The windings shown in the present drawings employ Wire of circularcross-section made of a suitable material to resist elongation,corrosion, electrolysis or other damaging effects in the Well. The wireis generally referred to by the reference numeral 20' and compriseswindings 21 and 22 located respectively on the end portions 14, 34, or35 of the body. The windings also include a central portion 23 whichpasses through one of the grooves 13 in order to join the two windings21 and 22. In FIG. 1, the specific locking means by which the windingends are held in place are not illustrated, but various means are shownin FIGS. 3, 4 and 5, wherein portions of the windings which correspondto those illustrated in FIG. 1 are provided with similar referencenumerals.

Referring now to FIG. 3, this figure illustrates an example in which thewire has a central portion which is passed through an opening in thebody, the opening generally being referred to by the reference character17. In some instances it may be desirable to line the opening 17 using arigid tube 18 so that the opening cannot be collapsed. This may also betrue where the windings take the form shown in FIG. 5 in which it may bedesirable to pass the finish end 22a of the winding through the body sothat it can be locked to the first turn of the winding 21a. Whenever arelatively rigid plastic body is used having an premolded or drilledbore 37 therethrough, the addition of tubing 18 is unnecessary since thepressure of the wire winding will not crush the opening 37 to anyconsiderable extent, as would be the case where a rubber body is used.In FIG. 3, the embodiment of the winding shown has its central portion24 passed through the body 16 initially. The windings 21 and 22 are thenwound from the outside toward the center 11 of the body, and the finalends of the windings 21a and 22a are then twisted together as at 25 inthe bottom of one of the grooves 13 or 33.

FIG. 4 shows an alternative embodiment in which a metal strap 26 is laidagainst the rod R prior to placing of the body on the rod. A more rigidplastic body would have to have a molded groove 38 along the bore 36 toreceive the metal strip 26. The strip 26 might also comprise a separatelength of wire which would pass through the body and extend a shortdistance out at both ends. The purpose of the member 26 is to lock thewindings ends 21b and 22b. With this type of arrangement, the centralportion 23 of the winding is first laid in the bottom of the groove 13and the winding is then applied, extending from the center out towardthe ends of the body portions 14. When the winding has been fullyapplied, its ends 21b and 2211 are passed through metal tabs 26a and 26bwhich are then hammered or crimped down in some suitable and well-knownfashion in order to lock the wires. In the case where the member 26comprises a short length of wire, its ends can then be twisted togetherwith the ends 21b and 22b to provide a lock. The metal strip ispreferable because it has less tendency to shift circumferentially ofthe rod R. As can be seen in FIG. 1, when the windings 21 and 22 arewound from the center outwardly on a rubber body, a ridge of the rubberis pushed outwardly along the end portions 14 of the body, so that whenthe last turn of the winding has been applied, there remains a ridge 19extending most of the way around the end portion and tending to hold thelast turn of the winding in place.

The further embodiment shown in FIG. 5 is modified to the extent thatthe underlying portion of the winding 24 passes through the body and isprovided with a hook 24a at one end. The winding 22 is first applied andthen the central portion 23 is passed over the central portion of thebody through a groove 13. Then the winding is applied, terminating in ahook 21c which is interwound with the hook portion 24c. Viewing the leftend of FIG. 5 as the bottom end of the scraper, this would provide onlyone lock located at the top of the scraper, which has the advantage ofplacing the locking means of the winding away from the lower end of thebody assembly, which lower end takes more wear and is more likely to bedamaged than the upper end of the assembly.

The type of winding shown in the drawing provides a novel securingmethod for applying a body to a rod, in which a length of the windingwire always passes the central portion of the body and joins ends of thewindings whose other ends are locked against unwinding by other lockingmeans so as to maintain the winding tension. In addition to the lengthof wire that is disposed longitudinally of the central portion of thebody, there is always one other locking means which is also disposedlongitudinally of the body and attached to the windings. The latter maybe a separate wire or metal strip, or it may comprise another portion ofthe winding wire itself.

The present invention is not to be limited to the exact embodimentsshown in the drawings for obviously changes may be made therein withinthe scope of the following claims.

I claim:

1. The method of attaching a resilient annular body having at least onelongitudinal passage therethrough to a rod-like member including thesteps of applying the annular body to surround the rod-like member;passing a length of wire winding material longitudinally through thepassage in the body; winding the material under tension plural timesaround both end portions of the body to compress them against therod-like member, and locking the ends of the wire material to maintainthe tension and prevent unwinding thereof.

2. The method set forth in claim 1 wherein the outer central portion ofthe body has plural longitudinally ex- 5 tending passages, including thestep of passing a locking member longitudinally under substantially thefull length of the body between it and the rod-like member, passing saidlength of wire material longitudinally through one 10 of said passagesin the central portion of the body and winding the latter in oppositedirections toward the ends of the body, and securing the ends of thewire material to the opposite ends of said locking member.

15 References Cited UNITED STATES PATENTS 1,950,678 3/1934 Hogan 140-1112,094,169 9/1937 Germany 166176 2,335,038 11/1943 Bridges 14093 303,099,889 8/1963 Verneuil 43--24 FOREIGN PATENTS 549,747 12/1957 Canada.25 1,360,248 3/1964 France.

CHARLES W. LANHAM, Primary Examiner.

L. A. LARSON, Assistant Examiner.

0 U.S. Cl. X.R.

